The political crisis in Madagascar has deepened, after transitional government head Andry Rajoelina backed out of power-sharing negotiations and named a former military officer as prime minister. Opposition groups have rejected the move and say they plan to name their own transitional government as part of an accord reached several months ago.

The head of Madagascar's transitional authority, Andry Rajoelina, announced a decree Sunday naming retired army Colonel Albert Camille Vital as prime minister.

On Friday, Rajoelina dismissed Prime Minister Eugene Mangalaza who had been named two months ago as part of a power-sharing agreement with three opposition groups.

He indicated he was withdrawing from the agreement and announced parliamentary elections would be held in March. The new parliament would choose a prime minister and draft a new constitution.

Rajoelina did not mention presidential elections. Under the current constitution the 35-year-old former mayor of Antananarivo is too young to run for the presidency.

The African Union, United Nations and Southern African Development Community have been mediating talks aimed at ending a crisis when Rajoelina, backed by the military, seized power in March after the departure of then-President Marc Ravalomanana.

The opposition groups, led by Mr. Ravalomanana and two other former Malagasy presidents, condemned the latest appointment as an illegal decision by an illegal power.

Vital, a former army officer who owns a private security company and heads the local chamber of commerce, said (in a nationwide broadcast) that the country was in a delicate, even frightening, situation and asked for the people's understanding.

He says a transitional authority is limited, unlike a presidential term, and it would be preferable to let the transition do its job in order to arrive at democratic and transparent elections.

He accused opposition parties of putting their own interests ahead of the national good and urged them to prove their popular support in a nationwide vote.

The opposition announced it would choose its own government this week and threatened to organize national protests. Months of demonstrations one year ago caused dozens of deaths, paralyzed the economy and led to the Rajoelina takeover.

The latest confrontation erupted after the three opposition groups, meeting in Mozambique earlier this month, chose a ministerial cabinet.

They left some cabinet posts for the Rajoelina group to fill. But Rajoelina, who had refused to attend saying the meeting was unnecessary, rejected the appointments and accused his rivals of seeking to undermine his authority.

He also rejected the appointment of two co-presidents agreed to at an earlier meeting by all four groups.

Analysts said the latest moves were meant to shore up Rajoelina's power with his hardline supporters and the military. But they added that they were also likely to alarm foreign investors and further isolate the Rajoelina government, which has been suspended from the African Union and Southern African Development Community.